The actor previews the upcoming episodes and explains to THR why an old flame is just the start of Michael's problems.

Michael and Nikita aren't going to be in paradise for long.

In Friday's episode of Nikita, Michael (Shane West) deals with his Division past when he encounters a past assignment, Cassandra (guest star Helena Mattsson), a woman he played boyfriend to under strict orders. "She comes into his life unexpectedly; it was the one time he did a mission where was a boyfriend type and he couldn't control his emotions," West tells The Hollywood Reporter.

With the guilt eating away at him and Nikita (Maggie Q) suspecting that there may be something else going on, in addition to the task at hand, the cracks are getting bigger and bigger. West chatted with THR about the trouble Cassandra causes for Michael and Nikita, dealing with the past and speculates about a midseason twist.

The Hollywood Reporter: In the next episode, Michael is helping out a former flame Cassandra and that'll cause some rifts. Is this a sign of things to come?

Shane West: It is a sign for things to come for now. Because they made the decision to bring Michael and Nikita together so quickly in the run of the show, it's very difficult to pull them apart -- and in correct ways. There has to be friction now. There doesn't have to be but [executive producer] Craig [Silverstein] feels it would be too boring to have a whole season of them being perfectly happy. I agree in certain ways. It's a legitimate rift with Michael and Cassandra. She comes into his life unexpectedly; it was the one time he did a mission where was a boyfriend type and he couldn't control his emotions. He'd rather kill someone or train someone than have to play the boyfriend.

THR: Will things from Michael's past surface that will affect Nikita's perspective on who this guy is or was?

West: No. What's cool about it is that Michael is a good guy. He would have been married and had that kid, gone straight into the Navy and would have been fine for the rest of his life. He is always going to be that person at heart. With the situation with Cassandra, you'll see that nothing was done wrong, nothing was done out of malice and he does care about her, not as much as he does Nikita of course. She easily cares about a million other characters, so it's the first time she gets hit with the thought that someone else can care for someone that's not her. She's going to have to deal with reality, which she doesn't know if she can handle right now.

THR: Ryan (guest star Noah Bean) will also be back in the fold in a future episode. Will he affect Michael and Nikita's relationship?

West: Maybe in the future. Michael and Nikita aren't great in that episode. They're having problems built off the Cassandra sitaution, but we'll find in that episode that Michael gets upset with her because of what Nikita always does, and that's making decisions for other people. So they have an argument. But the Ryan thing is essentially to get him out of the CIA jail he's in, so now that he's released we'll see what happens with him in the future.

THR: What else is in store for Michael?

West: Based off of episode five, Cassandra comes back later in eight. You're going to see he's going to figure out a lot in five and not a lot in five. Nikita's going to find out more than he does and she's going to tell him the truth. It's a serious deal. You'll see Michael in mission mode dealing with what comes along. Even if he's upset about certain things, he's got to deal with that and push his issues aside. You're going to see him more or less trying to come to terms with what happened in his past and now, his present. There's more you're going to learn about Cassandra that's a surprise, that Michael didn't know either. Up until this midseason point, he's pretty much along for the ride, confused, trying to figure out what to do. I'm sure there's going to be a huge midseason collision. I highly doubt it's going to be the end of the season the way this show goes.

THR: Will Michael have another confrontation with Percy (Xander Berkeley)?

West: They've got to get Percy out of jail first. I don't know if it's as necessary as having other people have confrontrations with Percy this year. I'd like to have it happen, but they did have it last year. It was great beating him up. Whether it's Michael actually killing him -- if it has to go that far, that's different -- but he has had some revenge. I think it's more, does Alex need more revenge on him or does Nikita need more revenge on him?

THR: Any upcoming fight scenes?

West: Michael trained Nikita so it's about time we show Michael a little bit more trained in his movs, in his motion. There was a little bit with episode two with me and Devon [Sawa, who plays Owen], the problem was that action scene got hacked to pieces. It was a big, awesome action scene. That was unfortunate because that was Michael's first foray into a different type of fighting style. But we've got a lot coming up, a lot in the Cassandra episodes.